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Existence of Solutions to Elliptic Equations with Variable Exponents and a Singular Term

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Communications in Mathematical Research 2016年第2期32卷 185-192页

作者： Chen xu-sheng School of Mathematics Jilin University

The purpose of this paper is to study a class of elliptic equations with variable exponents. By using the method of regularization and a priori estimates, we obtain the existence of weak solutions to these problems.

关键词： variable exponent singular existence

Influence of initial iron ore particle size on CO2 gasification behavior and strength of ferro-coke

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Journal of Iron and Steel Research International 2020年第8期27卷 875-886页

作者： Run-sheng xu Shu-liang Deng Heng Zheng Wei Wang Ming-ming Song Wei xu Fang-fang Wang State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Chair of Metallurgy Montanuniversitat LeobenLeoben A-8700Austria Wuhan Iron and Steel Co. Ltd.Wuhan 430081HubeiChina School of Energy and Power Engineering Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315800ZhejiangChina

Highly reactive ferro-coke has been widely studied due to its contribution to the energy saving and emission reduction in blast furnace ironmaking. To optimize the coking process of ferro-coke and improve its metallurgical properties, it is necessary to clarify the influence of initial iron ore on the strength, micro-morphology and CO2 gasification reaction behavior of formed ferro-coke. The effects of initial iron ore particle size (0.50–1.00, 0.25–0.50 and 0.074–0.125 mm) on the CO2 gasification reaction of ferro-coke were analyzed using thermo-analysis technique. In addition, the effects of initial iron ore particle size on the strength and morphology of ferro-coke were investigated by drum test, digital microscopy and scanning electron micro-scopy. The results show that iron reduced from iron ore has a great promotion effect on the CO2 gasification reaction of ferro-coke. The smaller the particle size of initial iron ore, the more intense the gasification reaction, and the lower the starting temperature for gasification reaction of ferro-coke. The results of kinetic calculation show that the apparent activation energy of ferro-coke decreases with the decreasing particle size of blended iron ore. The particle size of initial iron ore has a great impact on the strength of ferro-coke. The ferro-coke prepared by 0.25–0.50 mm iron ore presents the best strength in this experiment.

关键词： Ferro-coke Iron ore Particle size Strength Gasification reaction

Ni(OH)_(2) Derived from NiS_(2) Induced by Reflux Playing Three Roles for Hydrogen/Oxygen Evolution Reaction

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Chinese Journal of Structural Chemistry 2022年第8期41卷 52-57页

作者： sheng-Jun xu Ya-Nan Zhou Guo-Ping Shen Bin Dong Dongying Haike Ruilin Chemical Co. LTD.Dongying 257000China State Key Laboratory of Heavy Oil Processing College of Chemistry and Chemical EngineeringChina University of Petroleum(East China)Qingdao 266580China

Developing efficient and promising non-noble catalysts for oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) is vital but still a huge challenge for the clean energy system. Herein, we have integrated the active components for OER(Ni(OH)_(2)) and HER(Ni S_(2) and Ni(OH)_(2)) into Ni(OH)_(2)@NiS_(2) heterostructures by a facile reflux method. The in-situ formed Ni(OH)_(2) thin layer is coated on the surface of hollow Ni S2 nanosphere. The uniform Ni(OH)_(2)@NiS_(2) hollow sphere processes enlarge the electrochemically active specific surface area and enhance the intrinsic activity compared to NiS_(2) precursor, which affords a current density of 10 m A cm^(-2) at the overpotential of 309 m V and 100 m Acm^(-2) at 359 m V for OER. Meanwhile, Ni(OH)_(2)@NiS_(2) can reach 10 m A cm^(-2) at 233 m V for HER, superior to pure NiS_(2). The enhanced performance can be attributed to the synergy between Ni(OH)_(2) and NiS_(2). Specifically, Ni(OH)_(2) has three functions for water splitting: providing active sites for hydrogen adsorption and hydroxyl group desorption and working as real OER active sites. Moreover, Ni(OH)_(2)@NiS_(2) displays great stability for OER(50 h) and HER(30 h).

关键词： Ni(OH)_(2) NiS_(2) heterostructures oxygen evolution reaction hydrogen evolution reaction

The production of enantiopure D-lysine from L-lysine by a two-strain coupled system

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Chinese Journal of Chemical Engineering 2020年第11期28卷 2832-2836页

作者： sheng xu Xiaolu Lu Xin Wang Zhen Gao Kequan Chen Pingkai Ouyang State Key Laboratory of Materials-Oriented Chemical Engineering College of Biotechnology and Pharmaceutical EngineeringNanjing Tech UniversityNanjing 211816China

The microbial production of D-lysine to replace chemical approach has gained great interest with the rising concerns over the ***,we employed recombinant *** strain BL21-LYR with lysine racemase and strain BL-22A-RB-YB with L-lysine monooxygenase and 5-aminovaleramide amidohydrolase to establish a two-strain coupling whole-cell bioconversion system for D-lysine production from *** improve the optical purity of D-lysine,the optimal reaction condition for resolution of DL-lysine after the racemization was *** specificity of BL-22A-RB-YB for L^-lysine and the effects of reaction condition on bioconversion efficiency of whole-cell were accordingly *** the optimal condition,a maximum 53.5 g·L^-1 D-lysine and 48.2 g·L^-15-AVA were obtained with yield of 47.4%and 42.3%,respectively,by the microbial racemization and asymmetric degradation *** final D-lysine enantiomeric excess was over 99%.Meanwhile,a valuable compound 5-aminovaleric acid was synthesized with the production of D-lysine,indicating the economic feasibility of the two-strain coupling system.

关键词： _D-Lysine Microbial resolution Two-strain coupling system

Enhancing (de)hydrogenation kinetics properties of the Mg/MgH_(2) system by adding ANi_(5)(A=Ce,Nd,Pr,Sm,and Y) alloys via ball milling

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Journal of Rare Earths 2021年第8期39卷 1010-1016页

作者： Wenfang Liao Wenbin Jiang xu-sheng Yang Hui Wang Liuzhang Ouyang Min Zhu Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510641China China-Australia Joint Laboratory for Energy&Environmental Materials Key Laboratory of Fuel Cell Technology of Guangdong ProvinceGuangzhou 510641China Advanced Manufacturing Technology Research Centre Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHung HornKowloonHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518057China

Magnesium(Mg)-based alloys have already been widely studied as the hydrogen storage materials because of their high reversible hydrogen storage capacity,low cost,light weight,***,the poor de/hydrogenation kinetic properties dramatically hinder the practical *** this work,the MgH_(2)-ANi_(5)(A=Ce,Nd,Pr,Sm,and Y) composites were prepared by a high-energy ball milling *** can effectively refine the particle size thus improving the kinetic *** results reveal that the MgH_(2)-ANi_(5) composites mainly consist of Mg_(2)NiH_(4),MgH_(2) and rare earth(RE) hydride,which will be dehydrogenated to form Mg_(2)Ni,Mg and stable RE hydride ***,the asmilled MgH_(2)-ANi_(5)(A=Ce,Nd,Pr,Sm,and Y) composites with various A-elements can respectively contribute to a reversible hydrogen storage capacity of 6.16 wt%,5.7 wt%,6.21 wt%,6.38 wt%,and 6.5 wt%at a temperature of 300℃,and show much better kinetic properties in comparison to the pure MgH_(2) without any ***-situ formed Mg_(2) Ni and stable RE hydride(such as CeH_(2.73) and YH_(2)) might act as effective catalysts to significantly improve the hydrogen storage properties of MgH_(2).The present work provides a guideline on improving the kinetic properties of the Mg-based hydrogen storage alloys.

关键词： Mg-based hydrogen storage alloy Kinetic properties ANi_(5) Additives Rare earths

Numerical and Experimental Investigation of Hydrodynamic Interactions of Two VLFS Modules Deployed in Tandem

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China Ocean Engineering 2020年第1期34卷 46-55页

作者： WANG Yi-ting WANG xue-feng xu sheng-wen WANG Lei SHANG Yongzhi State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration(CISSE) Shanghai 200240China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Division of Research and Development Shanghai Shocktorm Ocean Engineering Co.Ltd.Shanghai 201306China

This paper numerically and experimentally investigates the hydrodynamic interaction between two semi-submersible type VLFS modules in the frequency domain. Model tests were conducted to investigate the relationship between interactions and wave headings. Numerical studies were performed by solving the radiation-diffraction problem and were validated against the experimental results. Motion Response Amplitude Operators (RAOs) were obtained from numerical and experimental studies. The dependency of the hydrodynamic interaction effect on wave headings is clarified. The influence of different wave periods on the motion responses of two-module VLFS and wave elevations in the gap is studied. The results indicate that the hydrodynamic interactions of the two modules are directly related to the wave headings and the periods of the incident wave. The shielding effect plays an important role in short wave, and the influence decreases with the increase of the incident wavelength. The numerical results based on the diffraction-radiation code can give a relatively good estimation to the responses in short wave while for long wave, it would over-predict the response.

关键词： hydrodynamic interaction numerical analysis model test two semi-submersible type VLFS modules

Synthesis and insecticidal evaluation of tetrahydroimidazo[1,2-a]pyridin-5(1H)-one derivatives

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Chinese Chemical Letters 2016年第1期27卷 7-10页

作者： xuan-Qi Liu Ya-Qin Liu xu-sheng Shao Zhi-Ping xu Xiao-Yong xu Zhong Li Shanghai Key Lab of Chemistry Biology School of Pharmacy East China University of Science and Technology Shanghai 200237 China Shanghai Collaborative Innovation Center for Biomanufacturing Technology Shanghai 200237 China

A series of novel tetrahydroimidazo[1,2-a]pyridine-5（1H）-one derivatives containing a electronegative pharmacophore（=CNO_2） were synthesized via practical aza-ene reaction and characterized by ~1H NMR,^（13）C NMR,^（19）F NMR and HRMS. Preliminary bioassays showed that some of the target compounds exhibited good insecticidal activity against brown planthopper（Nilaparvata lugens） and cowpea aphids（Aphis craccivora） at 500 mg L^（-1）. Among them, compound 11 h was active against brown planthopper at100 mg L^（-1）. The insecticidal activities varied significantly depending on the types and patterns of the substituents, which provided guidance for further investigation on structure modifications.

关键词： Neonicotinoids Tetrahydroimidazo[1,2-a]pyridin-5(1H) one Configuration Insecticidal activity

Facile three-component synthesis and insecticidal evaluation of hexahydroimidazo[1,2-a]pyridine derivatives

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Chinese Chemical Letters 2015年第1期26卷 1-5页

作者： Ye-Feng Fan Wen-Wen Zhang xu-sheng Shao Zhi-Ping xu Xiao-Yong xu Zhong Li Shanghai Key Lab of Chemistry Biology School of PharmacyEast China University of Science and Technology Shanghai Collaborative Innovation Center for Biomanufacturing Technology

A series of new hexahydroimidazo[1,2-a]pyridine derivatives were synthesized via convenient and practical three-component reactions. Preliminary bioassays showed that majority of the target compounds exhibited moderate to excellent insecticidal activity against cowpea aphids （Aphis craccivora）. Among them, compound 91 demonstrated significant activity with LCso value of 0.00918 mmol/L which was about 3.8-fold higher than that of imidacloprid （IMI）. Furthermore, the study of stereostructure-activity relationship of four isomers of 9k indicated that configuration played a key role in insecticidal activity of these compounds.

关键词： Neonicotinoids Hexahydroimidazo[ 1,2-a]pyridine Three-component reaction Configuration Insecticidal activity

Design,synthesis and insecticidal activity of novel anthranilic diamides with benzyl sulfide scaffold

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Chinese Chemical Letters 2013年第8期24卷 673-676页

作者： Yin-Bo Chen Ji-Ling Li xu-sheng Shao Xiao-Yong xu Zhong Li Shanghai Key Lab of Chemistry Biology School of PharmacyEast China University of Science and Technology

A series of novel anthranilic diamides with benzyl sulfide scaffold were synthesized,in which N-pyridylpyrazole moiety generally regarded as key pharmacophore was *** target compounds were characterized by ~1H NMR,^（13）C NMR,^（19）F NMR and *** preliminary bioassays indicated that half of the title compounds were endowed with good insecticidal activities against armyworm（Mythimna sepatara） at the concentration of 500 mg/L,Exhilaratingly,the synthesized compound 3a was also active against Tetranychus cinnabarinus at 100 mg/*** difference in activities between the target compounds was influenced by the substituents,which provided some hints for further investigation on structure modifications.

关键词： Anthranilic diamides Benzyl sulfide Synthesis Insecticidal activity